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*************************************************************************
*                                                                       *
*  Compiler Construction Tool Box                                       *
*  ==============================                                       *
*                                                                       *
*  Version 9209                                                         *
*                                                                       *
*  Copyright (c) 1989, 1990, 1991, 1992 by                              *
*                                                                       *
*  Gesellschaft fuer Mathematik und Datenverarbeitung                   *
*  (German National Research Center for Computer Science)               *
*  Forschungsstelle fuer Programmstrukturen                             *
*  an der Universitaet Karlsruhe                                        *
*                                                                       *
*  All rights reserved. GMD assumes no responsibility for the use       *
*  or reliability of its software.                                      *
*                                                                       *
*************************************************************************


Direct requests, comments, questions, and error reports to:

   Josef Grosch
   GMD Forschungsstelle
   Vincenz-Priessnitz-Str. 1
   D-7500 Karlsruhe 1
   Phone: +721-662226
   Email: grosch@karlsruhe.gmd.de


Distribution Format:
--------------------

The compiler construction tool box is available via anonymous ftp from
several file servers:

host                     number        directory

ftp.karlsruhe.gmd.de     192.76.241.16 /pub/cocktail
ftp.gmd.de               129.26.8.90   /gmd/cocktail
iraun1.ira.uka.de        129.13.10.90  /pub/programming/cocktail
ftp.rus.uni-stuttgart.de 129.69.1.12   /soft/unix/programming/compilerbau
ftp.th-darmstadt.de      130.83.55.75  /pub/programming/languages/compiler-compiler/cocktail
ftp.eb.ele.tue.nl                      /pub/src/cocktail
src.doc.ic.ac.uk         146.169.2.1   /languages/tools/gmd
gatekeeper.dec.com                     /.3/plan/gmd


The files or file trees are compressed: For UNIX tar and compress are used
(suffix: .tar.Z), for MSDOS zip is used (suffix: .zip).

To uncompress a file tree use:

   uncompress < tool.tar.Z | tar xvf -   or   unzip tool.zip


Alternatively, the toolbox is distributed on tape in uncompressed tar format
on the following media:

- DC300/600 data cartridge (streamer tape) 
- TK 50
- Exabyte
- 1/2" magnetic tape (1600 bpi)

To read a tape use:

   tar -xvfb /dev/rst0 20   or   tar -xvb 20   or similar commands


The directories and their contents are as follows:
--------------------------------------------------

directory       contents
------------------------------------------------------------------------
README          this file
Makefile        compilation, installation, and test of the tools (UNIX)
compile.bat     compilation  of the tools (MSDOS)
install.bat     installation of the tools (MSDOS)
test.bat        test         of the tools (MSDOS)
doc.ps          documentation in postscript format
doc.me          documentation in troff format, me macros
doc.doc         documentation in ascii format (without pictures)
man             manual pages  in troff format, man macros
rex             Scanner Generator
lalr            LALR(1) Parser Generator
ell             LL(1) Recursive Descent Parser Generator
bnf             Transforms Grammars from Extended BNF to Plain BNF
front           Common Front-End of Lalr, Ell, and Bnf
reuse           Library of Reusable Modules (needed for all programs)
common          Library for estra and ell
specs           Example Specifications for the Above Tools
cg              Common Program implementing Ast and Ag
                Ast = Generator for Abstract Syntax Trees
                Ag  = Attribute Evaluator Generator
puma            Transformation Tool based on Pattern Matching
l2r             Transforms Lex  input to Rex  input
y2l             Transforms Yacc input to Lalr input
r2l             Transforms Rex  input to Lex  input
rpp             Rex PreProcessor: rpp + cg extract most of a scanner
                specification out of a parser specification
estra           Transformation of attributed trees (prototype)
hexa            contains the scanner and parser tables of Rex and Front
                (= front-end of Lalr and Bnf) converted from binary to
                ascii hexadecimal representation
dos		directory containg the MSDOS version
bin             UNIX: shell scripts (my version), MSDOS: batch scripts
lib             executables, table and data files (for SUN 3/SunOS 4.0 or PC/MSDOS)
(mtc            Modula-2 to C translator)

The names of the subdirectories indicate the following types of information:

sub directory   contents
------------------------------------------------------------------------
src             source files in Modula-2
m2c             source files in C (generated from the Modula-2 sources)
src             source files in C (generated from the C sources for MSDOS)
c               source files in C (hand-written)
lib             data files, module skeletons
test            test environment for a tool


Documentation:
--------------

The directories doc.ps, doc.me, and doc.doc contain documentation in postscript
format, troff format (me macros), and in ASCII format (without pictures).
The documentation for UNIX and MSDOS is the same. Therefore the documents are
stored in the UNIX directory, only, they are not repeated in the 'dos' subdirectory.
The document entitled "Toolbox Introduction" in the files intro.ps, intro.me,
or intro.doc gives an overview and introduces into the toolbox. It should be
read first. The following documents are available:

Filename        Title
------------------------------------------------------------------------
intro           Toolbox Introduction
toolbox         A Tool Box for Compiler Construction
werkzeuge       Werkzeuge fu"r den U"bersetzerbau
reuse           Reusable Software - A Collection of Modula-2-Modules
prepro          Preprocessors
rex             Rex - A Scanner Generator
scanex          Selected Examples of Scanner Specifications
scangen         Efficient Generation of Table-Driven Scanners
lalr-ell        The Parser Generators Lalr and Ell
lalr            Lalr - A Generator for Efficient Parsers
ell             Efficient and Comfortable Error Recovery in Recursive
                   Descent Parsers
highspeed       Generators for High-Speed Front-Ends
autogen         Automatische Generierung effizienter Compiler
ast             Ast - A Generator for Abstract Syntax Trees
toolsupp        Tool Support for Data Structures
ag              Ag - An Attribute Evaluator Generator
ooags           Object-Oriented Attribute Grammars
estra           Spezifikation und Implementierung der Transformation
                   attributierter Ba"ume
puma            Puma - A Generator for the Transformation of Attributed Trees
trafo           Transformation of Attributed Trees Using Pattern Matching
(minilax        Specification of a MiniLAX-Interpreter)
(begmanual      BEG - a Back End Generator - User Manual)


References:
-----------

1.   J. Grosch, `Generators  for  High-Speed  Front-Ends',  LNCS,
     371, 81-92 (Oct. 1988), Springer Verlag.

2.   H. Emmelmann, F. W. Schroeer, Rudolf Landwehr, ` BEG - a Generator
     for Efficient Back Ends', Sigplan Notices, 24, 227-237 (Jul. 1989)

3.   W. M. Waite, J. Grosch and F. W.  Schroeer,  `Three  Compiler
     Specifications', GMD-Studie Nr. 166, GMD Forschungsstelle an
     der Universitaet Karlsruhe, Aug. 1989.

4.   J. Grosch,  `Efficient  Generation  of  Lexical  Analysers',
     Software-Practice & Experience, 19, 1089-1103 (Nov. 1989).

5.   J. Grosch, `Efficient and Comfortable Error Recovery in Recursive
     Descent Parsers', Structured Programming, 11, 129-140 (1990).

6.   J. Grosch, H. Emmelmann, `A Tool Box for Compiler Construction',
     LNCS, 477, 106-116 (Oct. 1990), Springer Verlag.

7.   J. Grosch, `Object-Oriented Attribute Grammars', in: Proceedings of the
     Fifth International Symposium on Computer and Information Sciences (ISCIS V)
     (Eds. A. E. Harmanci, E. Gelenbe), Cappadocia, Nevsehir, Turkey, 807-816,
     (Oct. 1990).

8.   J. Grosch,  `Lalr - a Generator for Efficient Parsers',
     Software-Practice & Experience, 20, 1115-1135 (Nov. 1990).

9.   J. Grosch, `Tool Support for Data Structures',
     Structured Programming, 12, 31-38 (1991).

10.  J. Grosch, `Transformation of Attributed Trees Using Pattern Matching',
     to appear (1992).


Machine Dependencies:
---------------------

All machine dependent code is isolated in the file System.c which is written
in C. This file is set up to work under UNIX and MSDOS. There are three
copies of this file in the following directories:

   reuse/c
   reuse/src
   reuse/m2c

The UNIX command 'install' is used during installation. Unfortunately, this
command is not as standard as it should be. If 'install' is missing on your
machine or it complains about the calls then the shell script in the file
hexa/install can simulate the desired behaviour.


Installation under UNIX:
------------------------

The Makefile at the global level controls the compilation and installation
of the individual tools. It activates the tool specific Makefiles.

Several tools use binary data files called Scan.Tab and Pars.Tab whose internal
representation depends on whether the machine is little-endian or big-endian.
All machines store integer numbers in a sequence of bytes with increasing adresses.
An integer number usually consists of four bytes where the bytes at both ends are
termed most significat byte (MSB) and least significant byte (LSB). Big-endian
machines store the MSB at the lowest address and the LSB at the highest address.
Little-endian machines store the bytes the other way round.
Big-endian are e. g. MC 680x0, SUN/3, SUN/4, SPARC,
little-endian are e. g. VAX, DEC Station, 80386, 80486.

Initially the binary data files are configured for big-endian machines.
To find out in which class your machine is in execute:

   make endian

To convert the binary files from big-endian to little-endian or vice versa execute:

   make bin.conv

Edit the first couple of lines in the Makefile to accomodate your needs.
To compile the programs execute:

   make

To install the programs execute:

   make install


Installation under MSDOS:
-------------------------

Requirements to run the binaries:

   - 80386 or 80486 CPU
   - at least 2 MB memory
   - DOS extender (go32, from DJ Delorie)

Requirements to compile the sources:

   - GNU C compiler (gcc, DJ Delorie's GCC port to DOS)
   - GNU make (called gmake on our machine)
   - ar and ranlib (archive handling)

The software of DJ Delorie's GCC port to DOS is available from:

    host:      grape.ecs.clarkson.edu
    login:     ftp
    directory: /pub/djgcc


Installation from the sources:

There are several batch files at the global level for compilation and installation
of the individual tools. These activate either tool specific batch files or
GNU make (gmake) which is controlled by tool specific Makefiles.

Define four environment variables describing two directories that will store the
batch files that control the tools and the binaries and data files of the tools.
UBIN and ULIB hold the same names as BIN and LIB but use the UNIX style
(/ instead of \). For example:

   set BIN=\usr\hacker\bin
   set LIB=\usr\hacker\lib
   set UBIN=/usr/hacker/bin
   set ULIB=/usr/hacker/lib

To compile the programs execute:

   compile.bat

To install the programs execute:

   install.bat

To test the programs execute:

   test.bat


Installation of the binaries:

Copy the directories bin and lib to an appropriate location and set up the
four environement variables as described above. That's it. To test the programs
execute:

   test.bat


Recent Changes
--------------

Version 9209:

- Port to MSDOS.

Version 9208:

- The scanner generator 'rex' and the parser generators 'lalr' and 'ell'
  allow to chose arbitrary names for the generated modules. Therefore, it is
  possible to have several scanners and parsers in one program.

- The length of a token and the lookahead in scanners generated by 'rex' is no
  longer restricted to 256 characters. Both, tokens and lookahead can be of
  arbitrary length. A restriction in the size of the tables generated by 'lalr'
  has been removed. Now it is possible to generate rather huge parsers.

- The attribute grammar tool 'ag' has been extended to generate attribute
  evaluators for well-defined attribute grammars (WAGs). The program checks
  grammars whether they obey this property. It is possible to access
  non-local attributes and to compute attributes on a restricted form of
  graphs.

- The auxiliary modules 'Errors' and 'Source' have been included into the
  library of reusable modules called 'reuse'. The 'Errors' module has been
  extended to support messages with a string argument. It allows to store
  the messages and print them sorted by the source position. An extra module
  named 'Positions' has been introduced in 'reuse', too, for the handling of
  source positions.

- The program 'cg' which implements 'ast' and 'ag' accepts several input files.
  Instead of one file that communicates a tree definition to 'puma' with the
  fixed name 'TREE.TS' it is possible to produce several of those with different
  names. This is of interest if different "views" have to be communicated.

- The extern declarations for malloc, free, and exit have been removed from
  the generated C code.

- All tools do not generate # line directives by default, only upon request.

- In case of fatal errors during the execution of generated modules a user
  defined exception routine can be called instead of the predefined 'exit (1)'.

Version 9202:

- The Toolbox contains a new tool for the transformation of attributed trees
  called 'puma'. It is based on pattern-matching. It replaces its predecessor
  'estra' and comes with documentation in English.

- The tool for abstract syntax trees 'ast' has been extended from single to
  multiple inheritance. So-called "subunits" allow the implementation of one
  abstract tree by several compilation units. The concept of "views" makes
  it possible to derive from a common specification several abstract syntax
  trees which represent subsets.

- The attribute grammar tool 'ag' has analogously been extended to process
  object-oriented attribute grammars with multiple inheritance. It supports the
  generation of several attribute evaluators that run one after the other.

- The error handling module for the parser generators 'lalr' and 'ell' are
  independent of the parser module or the grammar. The manual for these parser
  generators has been completely rewritten.

- The Modula-2 to C translator 'mtc' has a new code-generator. This brings
  big efficiency improvements: 30% smaller program, 10% faster, 75% less
  dynamic memory consumption. It generates ANSI C as well as K&R C.
  
- The sources of all tools are in ANSI C as well as in K&R C.

- All tools generate modules in the target languages C (ANSI + K&R), C++,
  and Modula-2.

- The interface to the operating system has been redesigned. It allows to
  switch IO operations between UNIX system calls and C library calls.
  This should assure much better portability.
  


              Compiler Construction Tool Box
              ==============================

     Rex (Regular EXpression tool) is a scanner  generator  whose
specifications  are  based  on  regular expressions and arbitrary
semantic actions written in one of  the  target  languages  C  or
Modula-2.  As  scanners sometimes have to consider the context to
unambiguously recognize a token the right context can  be  speci-
fied by an additional regular expression and the left context can
be handled by so-called  start  states.  The  generated  scanners
automatically  compute the line and column position of the tokens
and offer an efficient mechanism  to  normalize  identifiers  and
keywords  to upper or lower case letters. The scanners are table-
driven and run at a speed of 180,000 to 195,000 lines per  minute
on a MC 68020 processor.

     Lalr is a LALR(1) parser generator accepting grammars  writ-
ten  in  extended BNF notation which may be augmented by semantic
actions expressed by statements of the target language. The  gen-
erator  provides  a  mechanism  for  S-attribution,  that is syn-
thesized attributes can be computed during parsing.  In  case  of
LR-conflicts  unlike  other tools Lalr provides not only informa-
tion about an internal state consisting of a set of items but  it
prints a derivation tree which is much more useful to analyze the
problem. Conflicts can be resolved by specifying  precedence  and
associativity of operators and productions. The generated parsers
include automatic  error  recovery,  error  messages,  and  error
repair.  The  parsers  are  table-driven  and  run  at a speed of
560,000 lines per minute. Currently parsers can be  generated  in
the target languages C and Modula-2.

     Ell is a LL(1) parser generator accepting the same  specifi-
cation  language  as  Lalr except that the grammars must obey the
LL(1) property. It  is  possible  to  evaluate  an  L-attribution
during parsing. The generated  parsers  include  automatic  error
recovery,  error  messages,  and  error  repair  like  Lalr.  The
parsers are implemented following the  recursive  descent  method
and  reach a speed of 810,000 lines per minute. The possible tar-
get languages are again C and Modula-2.

Ast - A Generator for Abstract Syntax Trees

- generates abstract data types (program modules) to handle trees
- the trees may be attributed
- besides trees graphs are handled as well
- nodes may be associated with arbitrary many attributes of arbitrary type
- specifications are based on extended context-free grammars
- common notation for concrete and abstract syntax
- as well as for attributed trees and graphs
- an extension mechanism provides single inheritance
- trees are stored as linked records
- generates efficient program modules
- generates modules in Modula-2 or C
- provides many tree operations (procedures):
- node constructors combine aggregate notation and storage management
- ascii graph reader and writer
- binary graph reader and writer
- reversal of lists
- top down and bottom up traversal
- interactive graph browser

Ag - An Attribute Evaluator Generator

- processes ordered attribute grammars (OAGs)
- processes higher order attribute grammars (HAGs)
- operates on abstract syntax
- is based on tree modules generated by Ast
- the tree structure is fully known
- terminals and nonterminals may have arbitrary many attributes
- attributes can have any target language type
- allows tree-valued attributes
- differentiates input and output attributes
- allows attributes local to rules
- allows to eliminate chain rules
- offers an extension mechanism (single inheritance)
- attributes are denoted by unique selector names
   instead of nonterminal names with subscripts
- attribute computations are expressed in the target language
- attribute computations are written in a functional style
- attribute computations can call external functions
- non-functional statements and side-effects are possible
- allows to write compact, modular, and readable specifications
- AGs can consist of several modules
- the context-free grammar is specified only once
- checks an AG for completeness of the attribute computations
- checks for unused attributes
- checks an AG for the classes SNC, DNC, OAG, LAG, and SAG
- the evaluators are directly coded using recursive procedures
- generates efficient evaluators
- generates evaluators in Modula-2 (or C)

Puma - Transformation Tool based on Pattern Matching

- last but not least


A comparison of the above tools with the corresponding UNIX
tools shows that significant improvements in terms of error handling
as well as efficiency have been achieved:
Rex generated scanners are 4 times faster than those of LEX.
Lalr generated parsers are 2-3 times faster than those of YACC.
Ell generated parsers are 4 times faster than those of YACC.
The input languages of the tools are improvements of the LEX and YACC
inputs. The tools also understand LEX and YACC syntax with the help of
the preprocessors l2r and y2l.

The tool box is publicly copyable. It has been developed since 1987.
It has been tested by generating scanners and parsers for
e. g. Pascal, Modula, Oberon, Ada and found stable.

The tool box is implemented in Modula-2. It has been developed using our
own Modula-2 compiler called MOCKA on a MC 68020 based UNIX workstation.
It has been ported to the SUN workstation and been compiled successfully
using the SUN Modula-2 compiler. The tools also run on VAX/BSD UNIX and
VAX/ULTRIX machines. This should assure a reasonable level of portability
for the Modula-2 code. Meanwhile the sources exist in C, too.